Method of perforating gypsum lath



Oct. 1, 1946. L. N. SO'RENSEN 2,408,488

METHOD OF PERFORATING GYPSUM pm;

Original Fi led June 8, 1939 4 Sheets-Sheet 1 1946. L. N. SORENSEN2,408,488

' METHOD OF PERFORAIING GYPSUM LATH Original Filed June 8, 1939 4Sheets-Sheet 2 Oct. 1, 1946. SQRENSEN I i I 2,408,488

METHOD OF PERFORATING GYPSUM LATH Original Filed June 8, 1939 @2022zawa/"enaefi/ 4 Sheets-Sheet 3 Oct. 1, 1946. L. N. SORENSEN 2,408,488-

METHOD OF PERFORATING GYPSUM LATH Original Filed June 8, 19 39 4Sheets-Sheet 4 A Patented Oct. 1, 1946 NIETHOD OF PERFORATIN G GYPSUMLATH Louis N. Sorensen, Port Clinton, Ohio, assignor to The CelotexCorporation, Chicago, 111., a corporation of Delaware Originalapplication June.

278,212. Divided and this 8, 1939, Serial No. application August 27,1941, Serial No. 408,430

9 Claims.

This invention relates to the method of perforating gypsum lath or thelike in the ordinary course of manufacture and article resultingtherefrom, so that when the finished lath are delivered from the last ordrying operations no further operation is needed before the lath isready for use.

Heretofore the perforating operation has generally taken place after thelath have come through the dryer and have been bundled prior toshipment; the operation has been done by means of gang drills whichleave considerable dust in the packaged lath.

An object of this invention is to provide a perforated gypsum lath whichis free from dust; this is highly desirable as the dust falls into theeyes of the mechanic applying the lath; this particularly is true whenthe lath are being applied to ceiling joists.

Another object of this invention is to provide a means whereby the lathto be perforated is moved forward at intervals or steps to permit theperforating operation while the lath is at rest in the machine duringthe forward steps.

Still another object is to provide a means whereby the plugs cut fromthe lath, may be removed after the perforation is completed.

These and other objects may be seen and noted from the followingspecifications and its accompanying illustrations, in which:

Fig. 1 is a side elevation of the device and the carrier or conveyorupon which the lath moves. Fig. 2 is an enlarged top plan view of theperforator partly cut away,

Fig. 3 is an enlarged side elevation of the perforating device, partlyin section, the cutting position of the knives being indicated by thedotted lines.

Fig. 4 is a view similar to Fig. 3 but with the knives in the retractedposition and the slide in the forward position removing the plugs.

Fig. 5 is an enlarged fragmentary section showing one of the knives asthe perforation is completed and the plug thrust within the throat ofthe knife.

Fig. 6 is a similar view to Fig. 5 but with the knife retracted and theplug about to be pushed from the top of the rod.

Again referring to the drawings a chain It] is mounted over rolls H asillustrated in Fig. 1; adjacent a conveyor of which the driven rolls l2aare a part; the idler rolls I 2 serve to support the lath on its journeythrough the perforator. Cross bars l3 are secured on the chain theperiods between A chain 15 drives sprockets l6 and I! to which.

are secured pivotingcrank arms l8 and I9 respectively, said crank armsbeing secured eccentrically upon the sprockets l6 and I1 which aresecured within a frame 20 on a bearing mount 2|.

A driven sprocket22 is secured on a shaft23 which is driven by means ofa chain and clutch (not shown) from the main board machine drive. Thechain I5 is mounted on the sprocket 22.

A Wheel 25 is rigidly secured to the outer end of the shaft 23 and has ashort crank arm 26 eccentrically secured to the face thereof on a pivotpin 21, and said arm 26 has a plate 28 secured thereon at its oppositeend and a notch 29 therein, thus as the sprocket 22 and wheel 25 revolvewith the shaft 23, the short crank arm 26 moves in an eccentric manneragainst the face of the wheel 25, pivoting on the pin 21, and the freeend of the arm on which the notched plate 28 is secured moves backtoward the frame 20 until the revolution of the wheel causes said arm toagain slide forward whereupon the notch 29 therein engages a lug l4 andmoves the chain Illa forward approximately one foot.

The chain 10a drives a sprocket A which in turn drives a chain Mb whichengages the sprocket B causing the chain Ill to move forward in steps ofone foot or any other predetermined distance. Lath are delivered bymeans of a driven roll lZa to the idler rolls I2 where they are engagedby the bars I3-one of which is at each end of the lath to insure itseven travel through the perforator.

As the rotationof the wheel 25 continues the notched end of the arm 26moves away from the lug l4 and the motion of the chains l0, Illa, and lbceases until the operation is repeated. This causes an intermittentmovement of the lath 30 as it travels through the perforating machine;the synchronizing of the retraction of the short crank arm 26 with theupward thrust of the crank wheels [6 and I1 causes the perforation ofthe lath during thatinterval when the chain Ill carrying the lath 30through the perforator, is not moving forward. I

The long crank rods l8 and I9 are pivotally attached at the top thereofto a plate 3| through bearings 32. Rollers 33 mounted on bars 34 move upand down on the frame 20 and keep the perforating machine in a verticalplane.

Rods 35 mounted on the plate 3| through sleeves to serve to keep theplate in alignment with a fixed die plate 31 secured to the frame 20thereabove, the sleeves 39 being secured to the plate 3! by bolts 35.

The rods 35 pass through bearing sleeves 35 secured to the top surfaceof the fixed die plate 31 by bolts 49, and oil cups 4! lubricate thesliding bearing sleeve 36.

Secured rigidly to the plate 3! through sleeves 42 are circularperforating knives '23, and said knives are fastened to the plate 3! bymeans of a bolt "H and lock nut 12. Th bolt a l passes through the plate"iii to which the knife is welded, and engages in the bottom of theknifeplate 3|. The circular knives slide up and down on stationary rods 64secured to a fixed plate secured to the frame Eli.

The die plate 37 has apertures 4E therethrough directly above the knives23 and registering therewith. Plugs ll extend into the apertures 46 andare held in place by means of a plate 59 to which they are fastened bymeans of lock nuts so. Bolts 59 secured through the plate #39 arescrewed into the die plate 3? and are retained by lock nuts 75 asshownin Fig. 4 to secure the plugs t? in a set position within the aperturees.

The apertures it are of such diameter as will allow the circularperforating knives 3 to project therein, whereas the plugs M are smallenough to fit within the throat of the knive (i3.

. Thus as the knives $3 pass through the gypsum lath 3B, the circularplug or cutting 5! cut therefrom is thrust downward into the throat ofthe. knife 43 by the downwardly projecting end of the plug M as theknife enters the aperture at. This results in a cleanuniform cut withthe edges of the hole being smoothed by the troweling action of theknives as passing through them.

On the downward stroke of the perforating mechanism, the rods Mithrustin upward through the knives 43 as the said knives move downward,push the circular plugs 5! out of the throat of the knives ea.

As the perforating assembly moves downward an extension arm 52, which isslotted at 53 to encircle a rod 5 3, strike-s a nut 55 secured on theend of said rod, which is a part of a lever operating mechanism.

, The rod to is movably secured to one end of the balancing lever 56suspended on a-pivot post or hearing 5'! mounted on a plate 58 andsuspended within the frame 28 and secured thereto by any suitable means.

Movably secured to the opposite end of the ba lancing lever 55 is asecond rod 59, to the lower end of which is secured a weight 5%. Apivoting angular lever (ii is secured on a pivot pin 52 mounted throughthe rod 59 above and adjacent to the weight 69 The center portion of thepivoting angular lever BI is pivotally secured on a pin 63 mountedthrough a, bearing bracket 64 secured to the frame 26, the angular legfilo projecting downwardly within an aperture 55 in a slide 65.

The slide 6% is slidably secured through split guides 61 secured to thedie plate 31 and projecting downwardly therefrom, and cross bars 68 aresecured between the side bars of the slide 66; thus as the extension arm52 strikes the nut 55 on the rod 5 the balancing lever 56 dips downwardat that end, causing the rod 59 to move upward vertically. this drawsthe pivoting angular lever 6i upward, the angular leg 6la projectingwithin the aperture es in the slide 6% isthus thrust forward to avertical position as shown in Fig. a and the slide i thus drawn forward,the cross bars 68 brushing the circular plugs 55 from the rods 44.

When the pressure is released on the nut 55, by the perforatingmechanism again moving upward, the weight (it pulls the'rod 59 downwardto counterbalance the balancing lever 58 and the slide 66 moves back toits original position with the cross bars out of the path of the knives43.

Rails 69 secured to the frame by any suitable means such as an angularplate 69a, as shown in Fig. 3, apertures 691) being provided therein toallow the passage of the knives G3 I therethrough support the lath 39 inthe perforator.

The operation is evident from the above description but may be brieflystated as follows: The laths or pieces of plaster board 39 are advancedstep by step through the perforating machine. When the feed is stoppedthe sliding plate 3!, operated by the connecting rods l8 and I9 slidesup carrying with it the tubular knives 43 which cut the disks 5| fromthe lath, as illustrated in Fig. 5, the plugs 41 acting to force thecuttings into the bore of the knives or cutters. When the plate 3idescends the cutters are retracted and the fixed rods M eject the pieces5! from the knives as shown in Fig. 6, and then by the lever mechanismthe frame 66 is shifted laterally and its bars 68 dislodge thepiecesfrom the top of the rods 44, as indicated in Fig. 4. The operation isthen repeatedfor the next rows of perforations, and so on indefinitely.

The preferred method which I prefer to use in forming my novelperforated lath wherein the perforations are troweled smooth is to firstform the lath on the lath forming machine as at C. The lath after it hasbeen formed is allowed to set as it travels on the conveyor l2a. Theconveyor [2a is of such length that the time it takes for the lath totravel from the lath forming machine to the lath perforating machine,the lath has had time to partially set the cementitious' materialforming the inner lamination of the lath. Where a plurality of rows oflath are simultaneously formed on the lath forming machine, it ispermissible to allow some of the lath which are not to be perforated topass on directly into the drier D, while the lath which are to beperforated are shunted to one side of the main conveyor E20. to passthrough the-lath perforating machine. The shunt conveyor system to thelath perforating machine also permits the lath to set harder so that abetter finished perforation is had.

The continuous movement of the lath on the conveyor or shunted conveyor[2a is then transformed to an intermittent motion by the conveyor ll! ofthe lath perforating machine. The lath or plaster board is advancedstep-by-step through the perforating machine. As the lath is advanced,the lath is then perforated during the period when the intermittentlyactuated conveyor i0 is standing still. After the lath leave theperforating machine, they are transferred from the intermittentlyactuated conveyor H! to the continuously moving conveyor I211. The laththen are. conveyed to. the drier where they are completely dried. It isobvious from the above disclosed method of forming a perforated lath,that a novel lath has been formed wherein the perforations are troweledsmooth; and as the lath is dried, a hard smooth surface is formed withinthe case where the lath-are drilled.

It is evident that as'the lath is perforated, it

is also possible to form means such as partially perforated holes forthe reception of nails for starting the nails into the lath or plasterboard as it is erected. Referring. to Figures 1 to6inclusive, novelmechanism has been provided to partially perforate the lath asit travelsthrough the perforator with intermittent motion. There has been providedprick punches 13' in the form of'long slender rods pointed on one endand afiixed to the plate 3| in a suitable manner such as tapping theplate 3| and threading the ends of the prick punches 13, To look theprick punches in position, lock-nuts 14 have been provided.. The angularplate 69a is provided with V apertures 15 to permit the passage of theprick punches Has the plate 3! is actuated to perforate the lath as ittravels through the perforator with a step-by-step motion; It is,therefore, evi-, dent that as the plate 3! is actuated, the prickpunches 13 indent the" lath 30 at 76 as indicated in Figures 2, 5 and 6.Therefore, as the perforator is actuated, it is obvious that the lath 30will be partially perforated or indented with a series of indentationsalong the edge of the lath or throughout the face thereof depending uponthe desired pattern of perforations and there has been indicated only asimple pattern of indentations so that the method of indenting and theapparatus may be simply described. It is evident that a more elaboratepattern of perforation may be used without departing from the scope ofthe invention by providing an increased number of prick punches.Similarly, there may be formed indentations or other forms ofperforations which may be formed by this machine wherein the finishedlath has suitable indentations or perforations for applying variou clipsfor erecting the lath instead of the usual nailing operation.

In the foregoing specification and in the accompanying claims, the useof the words set or hardened, in referring to the board at or about thetime of punching, is to be understood as comprising the use of suchwords in the sense in which they are commonly used in the art involved.The set or hardening of the cementitious material at or about the timeof punching refers merely to the initial set or hardening of theocmentitious material which, with a gypsum core, results from the takingon of additional water by the calcined gypsum, Ca2SO4. /2H2O inconverting to Ca2SO4.2H2O, a set or hardened condition but with thematerial still wet. The set or hardened condition referred to is to bedistinguished from the finished pro-duct which, in its set or hardenedcondition, and dry, that is with the excess moisture evaporatedtherefrom, differs in its physical condition in that the initially setor hardened material is relatively soft and somewhat plastic, whereasthe finally set, hardened and dry material is brittle, and when out,broken or crushed tends to break down to a powder or dust.

It will be understood that this invention is susceptible of embodimentin various forms, which are illustrated in the accompanying drawings andthat thespecial details and methods of forming the lath herein set forthmay be varied to suit particular purposes without departing from thescope of invention.

6 r This application is a division of application Serial No; 278,212filed June 8, 1939.

What is claimed is:

1. The method of fabricating a perforated slab 2 of-building materialcomprising a layer of set or: hardened cementitious material adhered tosurfacing sheets, which comprises the steps forming theslab, allowing thslab to partially'set, positioninga selected portion ofthe slab over astationary plug anvil perforating the partially set slab, by areciprocating annular cutter in cooperation with the plug anvil, andtroweling the partially set cementitious peripheral of the perforationcausing the periphery of the perforation to be smoothed. r I l 2. Themethod of perforating a slab of building material comprising a layer ofset or hardenedcementitious material adhered to surfacing sheets, whichcomprises as steps: uniformly advancing theslab, changing the uniformmotion of the slab to intermittent motion, and between intermittentmovements perforating selected portions of the slab after it isintermittently advanced.

3. The method of fabricating a' perforated slab of building materialcomprising a layer of set or hardened cementitious material adhered tosurfacing sheets, which comprises the steps: forming the slab, partiallydrying the slab, advancing the slab by intermittent movement and betweenthe intermittent movements thereof perforating selected portions of theslab, causing the periphery of the perforation of partially drycementitious material to be troweled smooth, and further drying the slabwhereby a perforated slab is has with the periphery of the perforationsof the slab clean and smooth,

4. The method of forming indentations for nail markings in a, slab ofbuilding material comprising a layer of set or hardened cementitiousmaterial adhered to surfacing sheets, which comprises the steps: formingthe slab, allowing the slab to partially set, and indenting thepartially set slab on one face, the other face opposite the indentationfirmly supported whereby a pattern of indentations is formed on asurface of the aforesaid slabforming nail markings without deformationof the opposite surface of the slab opposite such indentations.

5. The method of forming indentations for nail markings in a slab ofbuilding material comprising a layer of set or hardened cementitiousmaterial adhered to surfacing sheets, which comprises the steps: formingthe slab, allowing the slab to partially set and indenting the partiallyset slab by forcing portions of one of the surfacing sheets on one faceinto the partially set portion of cementitious material the other faceopposite the indentation firmly supported whereby as the slab ofcementitious material dries, a pattern of nail indentations is formed onone face ofthe slab without deformation of the opposite surface of theslab opposite such indentations. 6. The method of fabricating aperforated and indented slab of building material comprising a layer ofset or hardened cementitious material adhered to surfacing sheets, whichcomprises the steps: forming the slab, allowing the slab to partiallyset, positioning the slab with respect to punching and indentingmechanism, the under surface thereof being firmly supported,simultaneously indenting and perforating the partially set slab, andtroweling the partially set cementitious peripheral of the perforationcausing the periphery of the perforation to be smoothed.

'7. The method of perforating and indenting a slab of building materialinto a pre-arranged pattern of perforations and indentations, whichcomprises: uniformly conveying the slab to be perforated, changing themotion of the slab from uniform to intermittent, positioning the slabunder a punching apparatus, and supported at the point of punching andsimultaneously, uniformly and intermittently perforating the slab untilthe slab is completely perforated and indentedinto a pre-arrangedpattern of perforations and indentations.

8. The method of perforating plaster board comprising the steps;intermittently advancing a sheet of substantially wet plaster boardalong a support means, reciprocating a gang punch with the punchingstroke thereof synchronized with the dwell period of the intermittentadvance of the sheet, punching the sheet with the gang punch, receivingin cavities in the punches the plugs cut from the sheet in punching andsubsequent to a punching stroke ejecting the cut out punchings from thecavities of the punches.

9. The method for perforating plaster board having a partially setcementitious core with adhered surfacing sheets which comprises thesteps of positioning the plaster board on a support, intermittentlyadvancing the plaster board along the said support, simultaneouslyreciprocating a plurality of annular knives to cut through the plasterboard and receive in their open interiors plugs of the plaster board cuttherefrom as a consequence of the reciprocation of such annular knives,the cut-out plugs then through continued reciprocatory movement of theannular knives ejected therefrom, the plaster board advanced and theannular knives reciprocated in timed relation whereby the annular knivesare reciprocated only during the dwell period of the intermittentadvance of the plaster board and the cut out plugs are ejected prior tothe completion ofthe reciprocatory motion of the annular knives andfurther movement of the plaster board being intermittently advanced.

LOUIS N. SORENSEN.

